In the current condition of continuous development of storage technology, Input/Output (I/O) devices that support various protocols, such as Peripheral Component Interconnect Express (PCIe) protocol, Ethernet protocol, Serial SCSI (SAS) protocol, Fiber Channel (FC) protocol, Infiniband (IB) protocol and non-volatile memory (NVME) protocol become increasingly varied. In application, these I/O devices should generally be connected with ports of a server that support corresponding protocols. However, the number of ports of the server that support various protocols is limited. Besides, the limited number of ports in the server has severely hampered function expansion of the server, or even the storage device and storage system. In addition, too many I/O devices connected to the server would also make the internal and external space of the server too crowded, resulting in a serious heat dissipation problem for the server, the storage device and the storage system.